Gastrinomas are the most common symptomatic, malignant PET in patients with or without MEN1 and sufficient numbers of these patients have been entered into our protocols to allow systematic assessment. Studies are now underway, evaluating the natural history of these tumors including the presentation and initial diagnosis and definition of factors determining prognosis. Our studies have identified a cohort of 25% of patients in whom the gastrinomas have aggressive growth and 25% who have multiple endocrine neoplasia type 1 (MEN1). During this year a prospective study of acid secretory changes in patients post gastrinoma resection was completed showing for the first time insights into factors regulating basal secretion in this time period;a collaborative study of the ability to resect pancreatic endocrine tumors(PETs) thought to invade/encase or involve major blood vessels was completed which showed this should not be a contraindication to surgery is is currently widely thought;an epidemiological study on PETs in Japan was completed , which showed a number of important differences from the West, and a number of consensus conferences and position papers on classification/treatment of various disease aspects were published.